The invention pertains to an air scoop-cyclone filter assembly with an air scoop for guiding untreated air, comprising an intake opening, a deflection area for deflecting the untreated air, and an exhaust opening; and with a cyclone filter for cleaning the untreated air, which is installed downstream from the air scoop and is connected to the air scoop in an air-tight manner, wherein a perforated plate is arranged in the cyclone filter to server as a filter intake opening.
DE 27 38 293 A1 of the applicant discloses an air filter device for a turbocharged internal combustion engine. A cyclone filter to clean the untreated air, the compressor of an exhaust gas turbocharger, a charging air cooler, and a dry air filter are arranged in the path taken by the air. The dust deposited in the cyclone filter is discharged from the cyclone filter by an exhaust gas blower.
The applicant is engaged in the series production of an air scoop-cyclone filter assembly with an L-shaped air scoop for guiding the untreated air and with a cyclone filter for cleaning the untreated air, the filter being installed downstream from the air scoop and connected to the air scoop in an air-tight manner. The air scoop-cyclone filter assembly is arranged in the path of the air as described in DE 27 38 293 A1. The air scoop has an intake opening, a deflecting area for deflecting the untreated air, and an outlet opening. The cyclone filter has a perforated plate as a filter intake opening, a first outlet opening for the charging air, and a second outlet opening, through which the dust is discharged. The perforated plate itself has a first pass-through area in the center with a large number of holes and an impassable edge area. A cyclone vent pipe is arranged in each hole of the perforated plate.
It has been found in practice that an increased amount of residual dust is found in the charging air of vehicles equipped with this air scoop-cyclone filter assembly when these vehicles are driven under congested, bumper-to-bumper conditions in a dusty environment or when driven in a desert. A large amount of residual dust in the charging air damages the impeller of the compressor of the exhaust gas turbocharger. The large amount of residual dust is attributable to the larger dust particles in the untreated air. These tend to settle at the geodesically lowest point of the air scoop-cyclone filter assembly. Because of the way in which the untreated air is deflected in the air scoop, however, an air vortex develops precisely in this area; this vortex picks up the larger dust particles and feeds them discontinuously back into the air stream.